From: Sten Gunterberg (sten@ergon.CH)
Date: Wed Jan 12 1994 - 04:51:41 CST

Hi Managers!

My original question was:
> Sun is claiming that SunLink PPP is not supported on SPARCstations IPC and
> IPX on the built-in serial interfaces (ttya/ttyb or zss0), supposedly because
> of "Known hardware problems". This is hard to believe for me. Is this really
> true or is it just a cabling problem (you know the funnly little serial
> connectors on IPC/IPXs) ?
> They claim you need an SBus HSI board to run SunLink PPP on IPC/IPXs.
> I don't think SunLink PP requires *synchronous* serial interfaces, or
> does it? I know that you need an HSI for X.25 (sync) on IPC/IPX.
> So, my question is: Has anybody SunLink PPP running on a IPC or IPX on the
> buildt-in serial ports? Perhaps I just need a special cable?

Well, the respondents certainly have different opinions and experiences with
this. They range from "Sun is telling you the truth, I had to live through
that problem" to "I run X.25 on a IPX" [therefore SunLink PPP should work].

I have included the relevant replies below so you can get the "full picture".

The "facts" so far are:
- The *separate* product SunLink PPP requires SYNC. [aha!]
- Solaris 2.3 includes asynchronous PPP. [not very helpful, I'm afraid]
- In the SunExpress catalog, you can order a "Mini DIN-8 to DB-25 X.25
  adapter cable for IPC/IPX" product code X989A (I don't know if this code
  is valid world-wide). [this is really interesting]

Some people advised me to use MST-PPP. Well, we already do for our Internet
connection (and I fully recommend it), so I knew about that. The problem is
that the customer in question (actually a customer of an associated company)
has already bought IPXs, SunLink PPP and the "necessary" HSI boards. I am
trying to determine, whether they really need those boards (and if they should
start calling Sun names :-)

Now the interesting part. Dunstan Vavasour apparently has X.25 running on an
IPX. Here's his story:
> You can run X.25 quite happily on a IPX (in fact, I do it).
> AFAIK, you can also run it on later IPCs, but not the early ones.
> There may be some other reason why you can't do it. [run SunLink PPP - Sten]
> Hmm, I'm not an X.25 guru, but here goes ...
> The early IPC's had onboard serial ports which were incapable at a
> hardware level of supporting synchronous protocols. We tried to
> install X.25 on one of these machines and, after weeks of Sun swearing
> it could be done, they relented and agreed the hardware wasn't up to
> it.
> The IPX had a suitably capable port from day one and, AFAIK, the later
> mods of IPC boards had synchronous capable serial ports too.
> Beyond that there's not a lot to tell. You need a special cable to
> convert the din sockets on the IPX to a 25 pin D-type, and the notes
> with the cable explain what the pin assignments are. It may be that
> there are certain clocking configurations which don't work, but it is
> OK for the configuration we use.

So, with the special cable you can apparently get X.25 to work in the
built-in interfaces. But what about SunLink PPP? My understanding tells
my it should be possible if X.25 works. Maybe some Sun guru is listening?

Well, I will forward my findings to my friends that have to deal with this
mess. Maybe they can put some "pressure" on Sun.

Many thanks to: (Birger A. Wathne)
        Dan Stromberg - OAC-DCS <> (Terry Britton) (Brad Zoltick - PSTAFF) (Peter Gross) (Mark Dykeman [5508]) (Dunstan_Vavasour)
        dec@idahub.UCSD.EDU (David Chavez )
        Christian Lawrence <> (Glenn Satchell - Uniq Professional Services)
        Lupe Christoph <>
        Piete Brooks <>


Here are the other (significant) replies
From: (Terry Britton)

Sun is giving you the correct answer. Unfortunately I have lived through this
problem. SunLink PPP runs in synchronous mode only. The IPC and IPX serial
ports run in asynchronous mode only. You can either purchase an HSI card or
a thrird-party serial card that runs in synchronous mode.

By the way Solaris 2.3 includes asynchronous PPP, if that is an option for you.

From: (Peter Gross)

I don't know anything about SunLink PPP, but the public domain software
dp-2.3 works very well on my IPC. I strongly suggest that you install
patch 100513-04 (tty jumbo patch) which fixes a long-standing bug in
Sun's on-board serial ports that prevented RTS/CTS flow control from
working on input.

From: (Mark Dykeman [5508])

I am using Morning Star PPP v.1.4 from Morning Star Technologies on the
built in serial port with no problems. I am running an IPX....but I am
using a dial-up modem....14k mnp4...good luck

From: dec@idahub.UCSD.EDU (David Chavez )

I suggest you forget about Sunlink PPP and get MorningStar PPP instead.
It is cheaper, better, very flexible and has excellent tech support.
You can contact them at I am using it at sites
all around the world on both leased line and dial-up circuits and am quite
please with the results.

From: Christian Lawrence <>

I am in the process of setting up the PPP bundled in with Solaris 2.3.
TFM states that it is only for ASYNC operation and for SYNC you must get
SunLink PPP. I do recall some problem running X.25 and SNA on these units
......maybe its the same problem (e.g. missing clocks ?).

From: (Glenn Satchell - Uniq Professional Services)

The serial ports don't have the clock signal (TRxC and RTxC) to allow
them to do synchronous transfer. It's not just PPP, but also X25, SNA,
etc, which aren't supported. Sunlink PPP is synchronous only. You might
want to look at the public domain pppd package which does asyncronous
ppp (I'm using it right now to send you this mail).

From: Lupe Christoph <>

*SunLink* PPP requires a synch line. Other PPP implementations do not.
Use Brixton's BrxPPP if you want a more flexible implementation.
(Note that Sun does not disclose details about the HSI/S that allow
Brixton to support it; you have to use the Aurora card for higher
speed synch.)

From: Piete Brooks <>

In Europe (at least) you can get a cable (or whatever) to make IPCs and IPXes
run X.25 (sync). That means that you can run PPP too ...

Sten Gunterberg,, /C=CH/A=arCom/P=EUnet/O=Ergon/S=Gunterberg/
These opinions are not my own. Someone typed them while I was getting a coke!

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